According to Zuo only 10 to 16 percent of the fuel a car consumes is used to drive — that is, to overcome road resistance and air drag. Most of the rest is lost to heat and other inefficiencies. Zuo believes that with clever engineering, this deficit can be reduced.

He says three major opportunities exist for recovering or generating energy while driving: the waste heat given off by the engine, the kinetic energy absorbed during braking, and the vibrational energy dampened by the shock absorbers.

Zuo estimates that a car’s shock absorbers should be able to provide between 100 and 400 watts of energy on normal roads and even more on rougher roads. By comparison, the average cell phone call uses about 1 watt. That corresponds to an increase in fuel efficiency between 1 and 5 percent, which would add up to an annual fuel saving of $13 billion to $19 billion.

His energy-harvesting shock absorber works by translating the vertical vibrations of the suspension into rotational motion that turns a generator. Transferring the energy directly to the car’s battery or electrical devices reduces the demand on the alternator.

The device – which can be retrofitted – has been tested on campus roads and has been able to harvest about 60 per cent of available energy. He hopes to increase this to 85 per cent.

Currently the system would not be cost-effective for car owners who drive less than an hour or so a day so Zuo plans to focus on applications for large commercial vehicles while working to reduce the cost.